Toshiba Satelite L20 wont boot

I use this computer for around 2 years already. but, from 4 months ago, it started to show strange behavior.
For example if I restart it, I have to wait for 5 - 10 minutes after it shut down to boot again.

It's still looking good. However, it was solved using a cooler. If the cooler is plugged, it can be restarted immediately.

However, the problem getting worser now. I can't boot my computer without cooler plugged into the laptop. Anyone know how to solve this?
Thanks....